Electric call-bell for pneumatic tubes



(No Model.)

L. STROUSEL ELECTRIC CALL BELL FOR PNEUMATIC TUBES. No. 513,345. Patented Jan. 23, 1894.

ME NATIONAL umoauvmuu com- WASHINGTON D e 'rn'rss ATENT Brion.

LEOPOLD STROUSE, OF BALTIMORE, MARYLAND.

ELECTRIC CALL-BELL FO R PNEUMATIC TUBES.'

SPECIFICATION forming part of Letters Patent No. 513,345, dated January 23, 1894.

Application filed April 6,1893. Serial No. 469,267- (No model.)

To aZZ whom it may concern.-

Be it known that I, LEOPOLD STRoUsE, a citizen of the United States, residing at Baltimore, in the State of Maryland, have invented certain new and useful Improvements in Electric Call-Bells for Pneumatic Tubes, of which the following is a specification.

This invention relates to an improvement in electric call-bells, and has for its object to provide an electro-magnetic call-bell which shall be operated when a call is to be made by a pufi of air through a tube.

My invention may be used for any desired purpose and I have shown it applied to my speaking-tube exchange, patented to me October 25, 1892, No. 484,982, and wherein a number of speaking-tubes from various parts of the building meet at the exchange where there is a short exchange-tube common to all the speaking tubes and wherein the exchange mouth-and-ear-piece is located.

As here shown, my invention is used to notify the exchange attendant when it is desired to make a connection between two speaking tubes and for indicating to him the particular tube through which the notification comes.

In the accompanying drawings, Figure 1, is a top plan view of the exchange-tube, and

showing the various speaking tubes leading to it, also the call-valve, contact-pieces, electric battery, and bell which are used in connection with each speaking-tube. Fig. 2, shows afront view of the exchange-tube. Fig. 3, shows a section on the line 3--3 of Fig. 2.

By reference to the drawings it will be seen that any one of the speaking-tubes can be put into communication with the exchange-tube, but when so connected the other speakingtubes are all shut out and closed by the exchange-valve, 'i. It is not feasible to blow into one of the speaking tubes and produce a whistle-signal in the exchange mouth-andear-piece, because each speaking tube is cut off by the valve, 45, from the exchange-tube.

Each one of the speaking-tubes, A, has an aperture, 0., which is closed by the hinged callvalve, B, made of some conductive metal. The said valve is hinged to the outside of the speaking-tube and a block, 0, of rubber or other insulating material upon which the valve-hinge is mounted, insulates the valve valve is swung back from its seat over the aperture, a, it will rest against the contact piece,

D. An electric battery, E, has wires, e, e, 1

connecting its poles one with the contact-piece, D, and the other with the hinge of the call- Valve, B, but since the hinge is insulated from the speaking-tube wheneverthe valve is open, there will be a circuit established only when the said valve is swung open making contact with the piece, D. An electric-bell F, in the exchange room is connected in the circuit so that whenever the said circuit is established, the said bell will ring a call. An arm, I), is secured at an angle to the call-valve, B, and has a balance weight, b, secured on the end thereof, for a purpose to be presently set forth.

The operation of the device is as follows: Suppose a hotel is supplied with the devices herein described l and a guest in one room wishes to converse with some one in another room. He blows down his speaking-tube and the force of his expiration lifts the call-valve which causes the weight, b, to be overbalanced and fall; in so doing, it will raise the valve entirely and swing it into contact with the contact-piece, D, which will complete the electric circuit and cause the bell, F, to sound, which will notify the exchange attendant, who will see by a glance which valve is open; the attendant can then switch the exchange mouth-and-ear-piece into connection with that speaking-tube upon which the open valve is located, by opening the valve, i, which. controls that particular speaking-tube, and thus put himself in communication with the guest and learn who it is the guest wishes to converse with and make the desired connection. The bell, F, will continue to ring till the attendant closes the call-valve, which will break the circuit.

My invention may be used in warehouses, hotels, or public buildings, wherever an air tube is employed.

Having thus described my invention, I claim as new and desire to secure by Letters Patent The combination of the air-tube normally an electric alarm-bell, the call-valve, and the closed at-its end and having an aperture; a contact-piece, as set forth. I0 call-valve on the air-tube and covering the In testimony whereof Iaffix my signaturein said aperture; a contact-piece adjacent the the presence of two witnesses.

call-valve; a balance weight, b, secured to the LEOPOLD STROUSE. valve and adapted when said. Valve israised v Witnesses: V to retain it in contact with the c'ontac't pi'ece; SAMUEL RUSENTHAL,

and an electric circuit comprising a battery, LOUIS M. ADLER. 

